Method and apparatus for automatically controlling output of laser diode

Abstract

A pickup of an optical reproducing/recording apparatus having a laser diode generating an optical signal with a current power value, and a laser diode power control device automatically controlling an output of the laser diode. The laser diode power control device has a sampler sampling the current power value of the optical signal from the laser diode, an operation unit outputting a target output value based on a comparison of the sampled current power value and a basic power value depending on a type of medium that is to receive the output of the laser diode, and a controller controlling the output of the laser diode based on the target output value.

1. A pickup of an optical reproducing/recording apparatus comprising:
 a laser diode generating an optical signal with a current power value; and 
 a laser diode power control device automatically controlling an output of the laser diode, wherein the laser diode power control device comprises
 a sampler sampling the current power value of the optical signal from the laser diode, 
 an operation unit outputting a target output value based on a comparison of the sampled current power value and a basic power value depending on a type of medium that is to receive the output of the laser diode, and 
 a controller controlling the output of the laser diode based on the target output value. 
 
 
   
   
     2. The apparatus of  claim 1 , wherein the laser diode power control device further comprises:
 a registering unit storing the output of the sampler prior to being received by the operation unit; and 
 a basic register unit storing the basic power value prior to being received by the operation unit. 
 
   
   
     3. The pickup of  claim 1 , wherein the sampler holds the sampled current power prior to the comparing. 
   
   
     4. The pickup of  claim 1 , wherein the basic power value is based on a format of the medium and a maker of the medium. 
   
   
     5. The pickup of  claim 2 , wherein the sampled current power value comprises a first plurality of bits, and the stored basic power value comprises a second plurality of bits, and the operation unit simultaneously compares ones of the first plurality of bits with corresponding ones of the second plurality of bits to generate the target output value. 
   
   
     6. The pickup of  claim 2 , wherein the stored sampled current power value comprises a first plurality of bits, and the stored basic power value comprises a second plurality of bits, and the operation unit simultaneously comparing ones of the first plurality of bits with corresponding ones of the second plurality of bits to generate the target output value. 
   
   
     7. The pickup of  claim 6 , wherein the first plurality of bits are indicative of a read power, a peak power and a bias power. 
   
   
     8. The pickup of  claim 6 , wherein the first plurality of bits are indicative of a read power, a peak power and a bias power of a sector of a medium which is to receive the output of the laser diode. 
   
   
     9. The pickup of  claim 6 , wherein the first plurality of bits are indicative of a read power, a peak power, an erase power, a cooling power and a bottom power of a sector of a medium which is to receive the output of the laser diode.